Syntax and consistent equation semantics of hybrid Chi
D.A. van Beek, Ka Lok Man, Reniers, J.E. Rooda, Ramon R. H. Schiffelers · 2004
† This work was partially supported by the EU project HyCon (FP6-IST-511368) ii The hybrid χ (Chi) formalism integrates concepts from dynamics and control theory with concepts from computer science, in particular from process algebra and hybrid automata. It integrates ease of modeling with a straightforward, structured operational semantics. Its ‘consistent equation semantics ’ enforces state changes to be consistent with invariants as in most hybrid automata. Ease of modeling is ensured by means of the following concepts: 1) different classes of variables: discrete and continuous, of subclass jumping or non-jumping, and algebraic; 2) strong time determinism of alternative composition in combination with delayable guards; 3) integration of urgent and non-urgent actions; 4) differential algebraic equations as a process term as in mathematics; 5) steady-state initialization; and 6) several user-friendly modeling extensions. Furthermore, the Chi language incorporates several concepts for complex system specification: 1) process terms for scoping that integrate abstraction, local variables, local channels and recursion definitions; 2) process definition and instantiation that enable process re-use,